Registered Extension Number




Ratification Status


Extension and Version Dependencies

API Interactions

  • Interacts with VK_KHR_ray_tracing_pipeline

  • Interacts with VK_KHR_synchronization2

SPIR-V Dependencies


Other Extension Metadata

Last Modified Date


Interactions and External Dependencies
  • Stu Smith, AMD

  • Tobias Hector, AMD

  • Marius Bjorge, Arm

  • Tom Olson, Arm

  • Yuriy O’Donnell, Epic Games

  • Yunpeng Zhu, Huawei

  • Andrew Garrard, Imagination

  • Dae Kim, Imagination

  • Joshua Barczak, Intel

  • Lionel Landwerlin, Intel

  • Daniel Koch, NVIDIA

  • Eric Werness, NVIDIA

  • Spencer Fricke, Samsung


VK_KHR_ray_tracing_maintenance1 adds a collection of minor ray tracing features, none of which would warrant an entire extension of their own.

The new features are as follows:

  • Adds support for the SPV_KHR_ray_cull_mask SPIR-V extension in Vulkan. This extension provides access to built-in CullMaskKHR shader variable which contains the value of the OpTrace* Cull Mask parameter. This new shader variable is accessible in the intersection, any-hit, closest-hit and miss shader stages.

  • Adds support for a new pipeline stage and access mask built on top of VK_KHR_synchronization2:

  • Adds two new acceleration structure query parameters:

    • VK_QUERY_TYPE_ACCELERATION_STRUCTURE_SIZE_KHR to query the acceleration structure size on the device timeline

    • VK_QUERY_TYPE_ACCELERATION_STRUCTURE_SERIALIZATION_BOTTOM_LEVEL_POINTERS_KHR to query the number of bottom level acceleration structure pointers for serialization

  • Adds an optional new indirect ray tracing dispatch command, vkCmdTraceRaysIndirect2KHR, which sources the shader binding table parameters as well as the dispatch dimensions from the device. The rayTracingPipelineTraceRaysIndirect2 feature indicates whether this functionality is supported.

New Commands

New Structures

New Enum Constants



  • Extending VkQueryType:



  • Extending VkStructureType:


If VK_KHR_synchronization2 is supported:

New Built-In Variables

New SPIR-V Capabilities


None Yet!

Version History

  • Revision 1, 2022-02-21 (Members of the Vulkan Ray Tracing TSG)

    • internal revisions

See Also

Document Notes

For more information, see the Vulkan Specification

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.

Copyright 2014-2024 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0